Throttle flowmeters play an important role in flow parameter measurement, but there are common defects such as large throttling losses, small range ratios, and high requirements for straight pipe sections. A flow measurement method based on improved static pressure difference method is proposed through the study of static pressure difference flow measurement method and the influence of pipeline constraints on flow measurement. Taking advantage of the introduced pipeline constraints and combined with static pressure difference method and fluid flow parameters, a flow measurement model based on support vector machine is established. Besides, Compared with the traditional throttling flowmeter (standard orifice plate), it shows that the method has no throttling loss, the flow measurement range is wide, and the measurement accuracy of fluid flow can reach less than 2%, which is suitable for the actual measurement of industrial parameters.